Effect of diketocoriolin B on antibody formation.

Sir: Most antitumor compounds have been known to be immunosuppressive, but in contrast, we found that intraperitoneal injection of diketocoriolin B (DKC)1} increases the number of antibody-forming cells in mouse spleen. Female dd/Ymice (5~6 weeks old, weighing 18~20 g) were immunized intravenously with sheep red blood cells (SRBC) and the numbers of antibody forming cells was -determined 48 hours thereafter by the hemolytic plaque technique2). Results are shown in terms of average number of plaque forming cells (PFC) per 108 spleen cells. One mg of diketocoriolin B was dissolved in 0.2ml of dimethylsulfoxide, then 1.8 ml à"of saline and a trace of Tween 80 (Wako Pure Chemical Ind. Ltd., Japan) were added. Each 0.2ml of saline-diluted solution was injected to mice intraperitoneally. MAY 1972